Method of making molded rubber articles, mold, and lubricant therefor



Patented Apr. 13, 1926.

UNITED STATES PATENT OFFICE.

BENTON DALES AND WILLIAM S. CABLE, OF AKRON, OHIO, ASSIGNORZS TO THE B. GOODRICH COMPANY, OF NEW YORK, N; Y., A CORPORATION OF NEW YORK.

METHOD OF MAKING- MOLDED RUBBER ARTICLES, MOLE. ANIIt LUBRICANT THEREFOR.

1N0 Drawing. Original application filed November 17, 1924, Serial No. 750,473. Divided and this appli v cation filed November 20, 1924. Serial No. 751,161.

To all whom it may concern: I

Be it known that we, BENTON DALES and WILLIAM S. CABLE, citizens of the United States, residing at Akron, in the county of Summit and State of Ohio, have invented certain new'and useful -Methods of Making Molded Rubber-Articles, Molds, and Lubricants Therefor, of which the following is a specification.

This invention relates to hollow rubber articles which are formed and vulcanized upon mandrels or cores, such as battery jars and the like, and is a division of our c0pcnd-' ing application Serial No. 750.473, filed Now e1nber.l7, 192

This invention has for an ol'lject to provide an improved method of making rubber articles of the character designated which. shall produce upon the vulcanized articles mandrel formed surfaces to which sealing compoundsnormally eu-lployed in securing the covers thereto will tightly and perinanently adhere. A further object is toproride an improved mandrel lubricant.

It has heretofore been the usual practice in the nmnn facture of battery jars and other one piece containers to coat the mandrel with soap or water-glass prior to the placing of .the rubber stock about the mandrel. These mandrel lubricants, socalled, prevent the adhesion of the rubber to the mandrel during vulcanization, but have the objectionable feature, for use in the manufacture of battery jars and like containers, that they leave on the val ranized article a water soluble film.

This disadvantage displays itself only after the jars are placed in service. Following the usual procedure, the covers are sealed into the jars, or containers, with a compound composed largely of pitch of some kind which forms an adequate seal as long as the jar is dry. WVhen the acid solution is placed in the jar, however, the water works up along the water soluble films be tween the jar and the sealing compound which holds the cover. The result is that the sealing composition is so loosened that from the jar after vulcanization, and. 5

jar leaks slowly and dissipates gradually the liquid content of the battery;

lVe have found that sugar cane wax is an excellent mandrel-lubricant, in that it effectively prevents adhesion of the vulcanized container to the mandrel, which readily slips cent solution being satisfactory, and brush or. spray the wax solution ov-r the mandrel. lloth the wax and the solvent should be substantially free of water soluble materials. When the-solvent has evaporated, the rubber stock is formed about the mandrel and vulcanized in the usual manner. The mandrel is readily removed from the vulcanized coutainer which has on the niandrel-fornuul surfaces a thin lilm. of the the sugar cane wax.

In case the containers are to be subjected to an electrical leakage test. before vulcanization, a solventfor the wax consisting in '7v whole or in part of carbon t'et'ri'ichlorhle should be used in order to prevent. tires and explosions during test.

WVe claim:

1. The method of preparing surfaces of members contacting with rubber during vulcanization which consists in coating the surfaces at least in part with a substantially water-insoluble composition comprising sugar cane wax.

2. The method of preparing surfaces of members contacting with rubber during vulcanization which consists in coating the surfaces at least in part with a solution containing substantially watereinsoluble materials including sugar cane wax.

A mold element coated at least inpart with a substantially water-insoluble composition comprising sugar cane wax.

l. A. mold element coated at least in part with a solution containing substantially Water-insoluble matarials including sugar consisting of film formed'from a solution cane Wax.

5. A non-adherent coating for surfaces terials including sugar cane Wax.

contacting with rubber (luring vulcanization In witness whercof We have hereun o Set 5 consisting of a substantially water-insoluble 0111 hands ll 14th day of November; 1994.

composition comprising sugar cane Wax.

- 6. A non-adherent coating. forv surfaces BENTON DALES. contacting with rubber during vulcanization WILLIAM S, CABLE.

containing substantially water-insoluble ma- 10 

